Cannot find the Apple Measure App for iPhone in the App Store.

Hey,

Apple’s New ‘Measure App’ is a build-in one,like the ‘Health App’.It is not available in App Store.Measure App is available in iOS 12 Update and it is only compatible with iPhone SE and above(Because it use Augmented Reality). I hope this information is helpful to you.

Thank You

Swipe down from any home screen and do a search for Measure. It should show if it's on your device.